The present invention refers to a pipe switch or multiport valve for pneumatically conveying bulk material, and in particular to a pipe switch of the type including a housing provided with a first port, a second port extending coaxially with the first port, and a third port having an axis extending at an angle of less than 90.degree. relative to the axis of the second port, with the housing accommodating a cock by which the first port is selectively connectable with the second port and with the third port.
In general, the cock or rotor of such a conventional pipe switch extends between side covers which are provided with coincidental brackets. These brackets project beyond the housing and form a forked attachment for the working cylinder, with its piston rod engaging the bent end of the exposed drive lever. Mounted upon the side covers of the housing are limit switches which are actuated by a cam connected to the lever. With such a pipe switch, the area of compressed air and the drive are sufficiently separated from the switch interior and thus from the product and transport fluid. However, under the aspect of accident prevention and operational safety, the exposed arrangement of movable parts is highly undesirable. Moreover, the arrangement of those parts at the respective side covers complicates a dismantling of the side covers so that a frequently desired cleaning of the pipe switch, which requires a removal of the side covers, becomes difficult.